Fused drop-out cutout



July 3, 1951 D. c. HUBBARD Erm.4 K' 2,558,957

F'USED DROPOUT CUTOUT Filed Aug. 8, 1949 4 Sheets-Sheet 1 lJ'uly 3, 1951D. C. HUBBARD ETAL 2,558,957 FUSED DRoPoUT CUTYoUT Filed Aug. 8, 1949 4sheets-sheet 2 75 2:67576 76 7? 79 72 40 /[V'T Y 'E' I l Q .l 46

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July 3, 1951 D. c. HUBBARD r-:rAL 2,558,957

FUSED DROPOUT CUTOUT 4 Sheets-Sheet T5 Filed Aug. 8, 1949 m N5 um July3, 19.51 D. c. HUBBARD Erm. 2,558,957

FUSED DROPOUT CUTOUT Filed Aug. 8, 1949 4 .Sheets-Sheet 4` INVENTORS.

Patented July 3, 1951 FUsED onor-OUT cU'roU'r David C. Hubbard andWilliam L. Hollander, Centralia, Mo., assignors to A. B. Chance Company,Centralia, Mo., a corporation of Missouri Application August 8, 1949,Serial No. 109,146

The present invention relates to fused dropout cut-outs, and isparticularly concerned with drop-out cut-outs of the type which mayutilize any standard universal fuse link now on the market, and whichmay be opened manually at the top as a disconnect, or openedautomatically at the bottom responsive to the rupture of the fuse link.

One of the objects of the invention is the provision of an improvedfused cut-out in which the lower contact of the fuse tube is ejectedfrom the bottom contact arm of the support upon rupture of the fuselink, so that the fuse tube will hang with its opening down before andafter operation, thus protecting the fiber liner of the fuse tube fromall adverse weather conditions.

Another object is the provision of an improved cut-out structure whichis especially adapted to delay the actual parting of the lower contacts,due to fuse link rupture, until after the arc has been extinguishedwithin the fuse tube, so that the arc will always be extinguished beforethe physical parting of the contacts takes place.

Another object of the invention is the provision of an improved cut-outadapted to pull the fuse link from the fuse tube even when the rupturingcurrents are too light to generate sufdcient gases within the fiberliner to eject the link rapidly.

Another object of the invention is the provision of an improved cut-outwhich is trip free in that the automatic mechanism, which controls itsopening responsive to the rupturing of aV fuse, may operate, even whenthe lineman is closing the upper contacts of the cut-out, in the eventthe fault still exists on the line. i

Another object is the provision of firm' stops to arrest theskyrocketing which is due to jet action, so that the contact springswill not be overstressed and so that the jet action will be employed toassure the retention of the upper trunnions by the upper contact arm aslong as the blast exists.

Another object is the provision of an improved mechanism for the lowercontact and ejector arm, by means of which the ejector arm is sorotated, responsive to the rupture of a fuse link, that the trunnion ismoved out of its supporting groove, so that it can be ejected by theaction of another spring carried by the contact supporting arm.

Other objects and advantages of the invention will be apparent from thefollowing description and the accompanying drawings, in which similarcharacters of reference indicate similar parts throughout the severalviews.

12 Claims. (Cl. 20o-114) Referring to the drawings, of which foursheets:

Fig. 1 is a side elevational view in partial section, showing a fuseddrop-out cut-out embodying the invention, with the two alternative openpositions, shown in dotted lines;

Fig. 2 is a top plan view, taken on the plane pf the line 2-2 of Fig. 1;

Fig. 3 is a bottom plan view, taken on the plane of the line 3--3 ofFig. 1, looking in the direction of the arrows;

Fig. 4 is a front elevational view, taken on the plane of the line 4-4of Fig. l, looking in the there are direction of the arrows;

Fig. 5 is a side elevational view of the upper contact arm and connectorfixture;

Fig. 6 is a fragmentary sectional view, taken on the plane of the line6--6 of Fig. 5, looking in the direction of the arrows;

Fig. 7 is a fragmentary sectional view, taken through the mechanism atthe bottom of the fused cut-out assembly of Fig. 1, with the parts inthe position which they assume when the fuse is ruptured, but before thecontact has Abeen ejected from the contact supporting arm;

Fig. 8 is a fragmentary sectional view, taken on the plane of the line8-8 of Fig. '7, looking in the direction of the arrows;

Fig. 9 is a sectional view, taken on the plane of the line Q-Slof Fig.'7, looking in the direction of the arrows;

Fig. 10 is a sectional view, taken on the plane of the line Ill-i0 ofFig. 9, looking in the direction of the arrows;

Fig. 11 is a fragmentary sectional View, taken on the plane of the lineII-il of Fig. '7, looking in the direction of the arrows;

Fig. l2 is a fragmentary sectional view, taken on the plane of the line|2-I2 of Fig. 7, looking in the direction of the arrows:

Fig. 13 is a fragmentary sectional view of the upper contact supportingarm, taken on a plane passing through the axis of the arm, showing amodification;

Fig. 14 is a fragmentary sectional view, taken on the plane of the lineH-M of Fig. 13, looking in the direction of the arrows;

Fig. 15 is a fragmentary sectional view, taken on the plane of the lineI5-I5 of Fig. 13, looking in the direction of the arrows.

Referring to Fig. 1, 20 indicates a fused dropout cut-out assembly,which may be supported from a cross arm 2l by means of a pair ofclamping brackets 22 clamped on the arm by tight bolts 23.

The clamping brackets 22 support an insulator 24 by means of a centralclampingband 25; and the insulator 24 is provided with reducedcylindrical portions at each of its ends for receiving the clampingbands 26, 21, which carry the contact arms that support the fuse tubeunit 26.

The upper contact arm may consist of a pair of the spring contacts 29,shown in Fig. 1, these contacts consisting of resilient wire bent intosubstantiall'y U shape, with two separate wires 38, 3 I, terminating atan easy bend 32.

One of the wires 29 preferably has a. full helical loop 33 forincreasing its resiliency. The wires 38, 3| are bent toward each otherat 34 and 35, being provided with transverse crossing portions 36, 31.The transverse portions 36 and 31 support the curved parts 38 and 39,each of which partially embraces the cylindrical trunnion 48 of the fusetube unit.

Beyond the curved portions 38, 39 the wires close slightly upon thetrunnion 'at the humps, indicated at 4| and thereafter the wires divergeat 42 and 43 to provide a bell mouthed opening for receiving thetrunnions and guiding them into the position of Fig. l.

The contact wire 3| has a yoke at =44, which joins two legs of similarshape. The contact wire 38 is bent upwardly at 45 and has a yoke at 46joining two Wires of similar shape. The curved ends 32 are made of thisshape so that they can be caught in the groove of a, connector fixture41, where they are clamped in grooves of similar shape.

The connector fixture 41 may consist of -a substantially rectangularbody 48, having an upward extension 49 that serves as a connector. Theintegral extension I49 has a through bore 58 and a partially sphericalsocket I.

The upper surface of this extension 49 is formed with a pair of Vgrooves 52, one on each side of the hole 58, for receiving the tap wire53 (Fig.5)

Referring to Fig. 12, this is a view showing the tap wire 53 clampedbythe connector bolt 54.

The connector bolt 54 has an annular head 55 with a through bore 56 forreceiving the tap wire. The annular head carries an extension 51 on eachof its opposite sides, for engaging the tap wire 63 above the V grooves52. 'Ihe annular head 55 has a threaded shank 58, which passes throughthe hole 56; and on the opposite side of the connector extension 49there is a spring washer 59 and a nut 68.

Referring again to'Fig. 5 and Fig. 6, the body 46 may be hollow, havinga rectangular hole 6| extending through it, this hole being bounded bythe sides 62, 63 and by the top 64 and bottom 65. The sides 62, 63 haveregistering apertures 66 for one screw bolt 61, and the otherregistering apertures 66 for the other screw bolt 69.

The sides are formed with an outwardly projecting ledge 18 below thewire 38 and a similar outwardly projecting ledge 1| above the wire 29.

At the left side of the body 48 (Fig. 5 and Fig. 6) there is a curvedgroove 12, which nts the curved end portions 32 of the two contact wires29 and 39 when they are placed inside the anges 16 and 1| outside of thebolts which pass through the holes 66 and 68.

The clamping band 26 may consist of two separate half cylindrical parts,indicated at 13, 14. On the left side these partly cylindrical bandshave a short attaching flange 15, which is joined by a through clampingbolt 16. On the right side of Fig. 2 these partly cylindrical bands 13,14

have a longer attaching flange 11, in each case with holes that registerwith the holes 66 and 68, for receiving the screw bolts 16, 1l.

The attaching ilanges 11 are thus adapted to engage on the outside ofthe connector iixture 43, to clamp the wires 29 and 38 in the grooves12; and the wires are also confined above and below by the flanges 18and 1| (Fig. 5).

The upper contact springs 29 and 38 are provided with initial tensiontoward each other so that they tendI to close the tapered opening, whichis formed by the portions 42, 43, but these portions are cammed apart bythe upper trunnion 48 of the fuse unit 28, so that the curved portionsgrip the upper trunnion 48 and provide a connection with a low contactresistance.

The fuse tube unit 28 comprises a tubular insulating member 88, Vwhichis provided with an insulating liner 8|, and the insulating tube 88supports an upper contact iixture -82 and a lowerv contact ilxture y83.The upper contact :fixture 82 comprises a substantially cylindricalmetal member which is threaded to receive the cap =84 that clamps theupper button which is carried by the fuse cable.

The cylindrical body of the upper contact 82 has a pair of integrallaterally projecting cylindrical trunnions 48 (Figure 2) and thesetrunnions are preferably arranged toward the outer side of the contactfixture 82, that is toward the right, so that the jet action from thelower end of the tube 88 tends to rotate the fuse tube unit 29 in aclockwise direction about the upper trunnions 48. This tends to keep thelower fixture 83 in engagement with its contact arm until the jet actionhas ceased, and prevents mechanical disengagement at the lower end untilthe arc is extinguished.

The upper contact .lixture--82 preferably has a downward extension 85 onits right side which carries an integral metal operating ring 86, bymeans of which the fuse tube unit is manipulated, using a fusedisconnect stick.

Both the fixtures 82 and 83 have cylindricalv bores for receiving thetube 88, and the tube may be secured in these fixtures in each case bytransversely extending riveted pins 81, which are arranged at such apoint that they merely groove the outside of the tube 88 and areinsulated and spaced from the fuse cable.

The lower contact fixture 83 has a cylindrical body provided with thebore 88 for tube 88, and bore 88 communicates with a downwardly openblast chute 89. This blast chute comprises a pair of parallel side walls98 and a curved rear wall 9|, which extends at its lower edge to theaxis of the tube 88 and tends to direct the gases forwardly anddownwardly toward the right, away from the operator.

The lower contact fixture 83 has a laterally projecting body 92 which isprovided with a cylindrical bore 93 for housing a compression coilspring 94. In addition to housing the coil spring the extension 92carries an integral manipulating ring 95 which may be engaged by adisconnect stick or the like.'

'I'he extension 92 also carries a pair of pivot ilanges 96 which areparallel to each other and provided with a through bore for receivingthe pintle 91 of a fuse ejector lever 98. The fuse ejector lever 96comprises an elongated metal member which may have a flat body 99,generally surrounded by laterally projecting border flanges |36.

'(6 The flat body 99 carries a cylindrical hinge formation atl its rightside (Figure '1) for receiving the rivet 91. bymeans of which theejector lever 98 is pivoted.' The end wall of the ilxture extension 92is indicated at |02, and it is curved about the hinge formation I0| andhas a flat stop surface I 03 at its end for definitely limiting thepivotal movement of the elector lever 98 by engaging the fiat side |04.

The ejector lever 98 has a V-shaped notch |08 formed on the side towardthe compression spring 94, and a bifurcated metal strut |06 has its legsextending on both sides of the body 99 of the ejector lever in thisnotch |05.

The border wall |00, previously mentioned, engages the lower side of thestrut |06 and keeps it from sliding out of the notch |05 in Figure 7.The other end oi' the strut |08 has an end portion |91 of reduced widthwhich passes through an aperture in a metal disc |08 and extends intothe spring 94. Thus the spring is enabled to bear upon the strut |06 bymeans of the disc |08, and spring 94 urges the ejector lever 98 in aclockwise direction about its pivot 91.

The ejector lever 98 also carries a tubular portion |09, the details ofwhich are shown in Figure 9, and this tubular portion has a through bore|I0 for receiving a clamping button III. The clamping button III has atubular part |I2 extending into the bore IIO, and has a circular head|I3 for clamping the cable leader ||4.

The tubular part ||2 has a threaded .bore I5 for receiving the threadedportion I I6 of a screw bolt having a wing head I I1. The annular lowersurface ||8 of the wing head engages the end of the tubular portion |09.As the wing head I|1 is turned clockwise it is threaded into the buttonIII, and draws the button head II3 inward, clamping the leader I |4.

The ejector lever 98 also has a tapered extension I I 9, Figure 7, whichterminates in a grooved end |20, the two legs |2| of which are locatedon the two sides of the fuse leader |I4. Thus the fuse leader may betensioned, as shown in Figure 1, by pivoting the ejector levercounterclockwise from the position of Figure 7 to that of Figure 1,compressing the spring 94; and thereafter passing the leader ||4downward through the groove |20 in the ejector lever 98, and backwardtoward the left about the clamping button where the end of the lever issecured by turning the wing nut I I 1.

The ejector lever also carries a pair of integral laterally projectingtrunnions |22, Figure 7, and these trunnions are adapted to provide apivotal support for the fuse tube unit 28 on the lower contact fixture.

When the fuse tube unit is provided with a fuse as shown in Figure 1,the ejector lever 98 is held rigidly in fixed position with respect tothe fuse tube unit 28. The trunnions |22 are located lowermost below thepivot 91 of the ejector lever, as shown in Figure 1.

The ejector lever has a tapered rearward extension |23, Figure 1, whichis provided with a transverse pin |24. This pin engages the free end ofa wire spring 25, which is used at a certain stage in the operation ofthe cut-out to eject the lower contact fixture 83 from engagement withits contact arm, which will now be described in detail.

The lower contact arm is carried by the clamping band 21. This clampingband may be constructed just like the upper clamping band 26, and itsattaching flanges |26, |21, Figure 3, are apertured to receive the twoscrew bolts |28, |29.

These screw bolts |28, |29 support a lower contact arm iixture |30. Thecontact arm fixture |30 has its rear or left end hollow, having arectangular through aperture I3| provided with a top wall |32, a bottomwall |33 and a pair of side walls |34, Figure '1. 'I'he side walls |34are apertured to pass the screw bolts |28, |29, which pass through theseside walls and through the clamping flanges |28, |21 to secure thecontact arm fixture |30 to the clamping band 21.

The contact arm fixture |30 is formed with a hood for enclosing themechanism, this hood being open at the bottom and the front side, Thehood is formed by a rear wall |35, a pair of side walls |36 and a topwall |31. The same screw bolts |28 and |29, previously mentioned, areused to support the spring |25. Spring 25 has one end provided with acircular loop |38 extending about the screw bolt |28. It then has adiagonal portion |39 and a curved portion |40 which extends over thebolt |29 and terminates in a relatively straight free end portion |4|.

'I'he spring |25 may be U-shaped, having a transverse yoke |42 at itslowermost portion, in Figure '7, and there may be two legs which engageabout the bolts |28, |29. Thus the yoke |42 may be located transverselyof the border wall |00 of the ejector lever 98, so that the spring |25engages the left side of the ejector lever and tends to force the entirefuse tube unit toward the right, away from the hooded fixture |30.

The fixture |30 also carries a connector similar to the one described indetail in Figure 5, this connector being carried by an integral flange|43 which carries a threaded bolt with an elongated head I44. The tapwire is indicated at |45.

-The side walls |36 of the hood, of fixture |30, are closer together atthe bottom, as seen in Figure 3, having an offset at |46. Ihis osetportion is formed with an inwardly open groove |41 on the inside of eachside wall for receiving the laterally projecting trunnions |22 on theejector lever 98.

The inwardly open grooves |41 on the side Walls |36 extend backwardlyand upwardly in Figure '1, being defined on the right side by thepartition |48. On the rear side the groove is defined by a curvedsurface |49 so that the groove is rearwardly open to receive thetrunnions At its lower end the groove |41 has a cylindrical portion |50,where the trunnions |22 come to rest. The curved wall |49 extends upwardto a curved corner I5|, and is joined to a substantially straight topwall |52, which extends forwardly and downwardly out of the open side|53 of the hood.

The opening between the wall |52 and the partition |48 tapers backwardlyand becomes wider forwardly, and the wall portions indicated at |54 aremore widely spaced than the wall portions I36. Wall portions |54 arespaced widely enough to clear the ends of the trunnions |22.

The operation of this part of the cut-out is as follows:

Assuming the fuse tube unit 28 has been provided with a fuse and theejector lever has been tensioned, and the cable lead secured by beingclamped under the button the fuse tube unit may be lifted by adisconnect stick, the end of which passes through the ring 95.

The fuse tube unit 28 will then hang downward from the ring 95, beingupside down, as shown in dotted lines at the bottom of Figurel. With theunit in this position the ring is out of the hood and the trunnions |22arelocated uppermost, projecting laterally in both directions.

The contact fixture 85 may then be inserted into the contact arm iixture|30, or hood, and the trunnions |22 will pass below the wall |52 andabove the partition |48 until the trunnions |22 reach the 4curved backwall |48, 'I'hen the fuse tube unit may be permitted to settle down andthe trunnions |22 will pass into the groove |41' and come to rest uponthe curved portion |80, winch serves as a bearing.

'Ihe :use tube unit is now in the position shown in dotted lines at thebottom of Figure 1. The operator may then remove the disconnect stickfrom the ring 85 and place it in the ring 88, and by manipulating thestick the operator may rotate the fuse tube unit 28 counterclockwise, inFigure 1, on itstrunnions |22, in the lowerbearing |50, until the uppertrunnions 40 move into the tapered opening 48, 44 between the contactsprings 28 and 88.

The counterclockwise motion is continued until the upper trunnions 40spread the contact springs and move into the curved portions of thesewires behind the hump 4|. Then the upper contact contact springs 28 and8l so that these contact springs are not damaged.

' as to permit pivotal movement about the bolt |58.

Referring. to Figures 1a w 15, there show a modiiied iorm of uppercontact arms for engaging the same iusetube unit. In this case'the upperclamping vband 28 has itsattaching flanges The iixture |58 has anintegral upwardly extending ilange |68,l with a connector bolt |54,similar to those previously described for securing the tap wire |85.Fixture |58 extends forwardly toward the right from the box-likeportion'-|58,

wires wm `retain the upper trunnions 4o, but it is possible to use thedevice as a manual disconnect by merely pulling on the ring 88 with adisconnect stick. Such a pull would move the i'use tube unit 28clockwise to the position at the bottom left of Figure 1, indicatingthat it was purposefully opened as a disconnect.

I'he operational the fused cut-out, upon occurrence of a fault in thecircuit which melts the fuse, isas follows:

When the fuse melts, the tension on the leader ||4, which is caused bythe spring 84, and ejector lever 88, pulls the leader I4 out of the tube80, and the ejector lever 88 is permitted to rotate from the position ofFigure 1 to that of Figure 7.

During this rotation of the ejector lever, the trunnions |22 move in anorbit about the ejector lever 88, pivot 81, and the groove |41 issuitably curved to define this orbit. 'Ihus the trunnions |22 moveupward out of the groove |41 until when the ejector 'lever comes to astop the trunnions |22 are out of the groove |41 and in the open portionvoi! the hood which opens out at |53.

In the meantime the spring |25 has been engaging the ejector lever,tending to move it toward the right, but the spring 84 is stronger andthe spring 84 causes the ejector lever to rotate counterclockwise to theposition of Figure 7, when the stop surface |03`engaged by side |04limits further movement of the ejector lever.

The spring |25 then comes into play and it urges the ejector lever andthe whole contact fixture 83 toward the right, in Figure '1, electingthe contact fixture 83 from the hood |30, aiding the force oi.' gravitywhich tends to produce this same result.

The Jet action which is caused by the blast o! gases out of the lowerend of the tube 80 tends to rotate the fuse tube unit 28 clockwise atits lower end about the upper trunnion 40. This jet action Itends tokeep the lower contact xture 83 in the hood until the jet action hasstopped.

I'he jet action is resisted by the ring 85 engaging the inside of thetop wall |31, which is preferably provided with a downward curve at |55,tending to trap. the ring 85 under the hood until the jet action hasceased. This deilnite stop, provided by the top wall |31 engaging ring85, prevents the jet action from over-tensioning the upper and has adownwardly open cylindrical socket |88 for receiving a compressionspring |81.

In general, the fixture `|58 is. open on its lower side, being protectedon its upper side by a top wall |88, which protects the mechanism, andby a pair of side walls |88 which protect and enclose both sides of theupper mechanism.

The side walls |88 are parallel to each other and are provided withapertures for receiving rivets or pins |10, which provide a pivotalsupport for a lower rigid jaw member |1I`. The jaw member |1| comprisesa metal casting of substantially U-shape, having a pair of legs |12,|13, which are angular in cross section and which are provided -with anoutwardly curved end portion |14 for guiding the fuse tube unit betweenthe legs.

The yoke |15 may carry a triangular extension |18, with an upwardlyextending integral pin |11 for engaging the spring |81. 'I'hus thespring |81 urges the lower jaw |1| counterclockwise, tending to clampthe upper trunnions 40.

The legs |12, |13 may have a partially cylindrical depression at |18,Figure 13, where they are intended to engage the trunnions 40; and thetop of these legs |13, |14 may be provided with a downwardly curved endportion |18, to provide a tapered opening for guiding the trunnions' 40into the space between the hood |58 and the loger law |1|.

a nood. The top wan lss and sidewalls lss devfine a. downwardly openbox-like member whichv has an oiset |80, Figure l5, on each side, theoil set supporting downward wall extensions |'8|.

The offsets are not straight from front to back or left to right, butare formed with a partially cylindrical portion |82, Figure 13, which isopen downwardly and toward the right in Figure 13. Thus the partiallycylindrical portion |8| of the hood is opposed by the partiallycylindrical portion |18 of the lower jaw I1 f These two partiallycylindrical portions close about the trunnion 40, retaining `it betweenthe jaws but permitting rotation. Thus the fuse tube unit can rotateabout the upper trunnions 40 when the fuse blows or it can be used as adisconnect by using the upper ring |83.

This upper contact xture has the facility of adjusting itself to fusetube units of diierentlength, as may be encountered due to the ordinaryin accuracies resulting from mass production. If the fuse tube unit islonger, its trunnions 40 will engage the llower side |84 of offsets |80and tend to pivot the casting |56 clockwise about the bolt |58, thisbeing permitted by the elongated aperture IGZ.

' It the fuse tube unit is shorter than usual the upper contact iixture|56 may pivot in the opposite direction.

It will thus be observed that we have invented an improved fuseddrop-out cut-out which has the following advantages:

1. It is adapted to use standard universal fuse links of anymanufacturer and to be handled according to conventional practice.

2 The lower contact of the fuse tube is ejected from the bottom contactarm upon rupture o! the fuse link so that the fuse tube will hang withits opening extending downward after operation, thus protecting theinterior of the fuse tube from all adverse weather conditions.

3. The construction of the mechanism is such that the mechanical openingof the lower contacts is delayed until the arc has been denitelyextinguished. i

4. The jet action from the lower end of the tube tends to keep the upperend of the fuse tube in its proper position and to hold the lower end inposition untii after the blast, thus delaying mechanical opening untilthe arc has been extinguished.

5. The resilient spring contacts with their wide flaring ends areadapted to register with the trunnions ofA the fuse tube units, eventhough the dimensions may vary due to manufacturing tolerances and thecontacts may give suillciently to become self-aligning as they engagethe trunnions.

6. Any undue strain on the spring contacts is prevented by the provisionof stop surfaces which take the thrust that is caused by jet actionduring rupture of a fuse.

'7. The present fuse unit may be operated as a disconnect switch, butwhen so operated its automatic mechanism is still trip-free, so that afault on the line will open the lower contacts even while the operatoris closing and holding the upper contacts.

8. The device givesa visual indication at all times whether it isactively in the circuit or whether the circuit has been brokenpurposefully at the top or automatically by rupture of a fuse at thebottom.

9. The present device is adapted to effect a self-alignment of thecontacts and to accommodate manufacturing tolerances in the length ofthe fuse unit independent of the portions which grip the contacts.Shocks which might be imparted to the fragile fuse link element upon theclosing of the fuse tube unit with its contact arms are substantiallyreduced and practically eliminated, as the slamming of thefuse tube intoposition forces the ejector arm against the bottom of the fuse tube anddoes not tend to place additional tension on the fuse link element.

While we have illustrated a preferred embodiment of our invention, manymodifications may be made without departing from the spirit oi theinvention, and we do not wish to be limited to the precise details ofvconstruction set forth, but desire to avail ourselves of all changeswithin the scope of the appended'claims.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent of the United States. is:

1. In a fused drop-out cut-out, the combination of an insulating supportwith upper and lower 10 fuse tube unit comprising an insulating tube ope.at the bottom and closed at the top. said tube having upper and lowercontact iixtures and supporting and enclosing a tensioned ruse engagingsaid nxtures, both said xtures being provided with a pair of oppositelydirected aligned trun urging said ejector lever about its pivot totension the fuse and to move the ejector lever tru'nnlons backwardly andupwardly in an orbit, said lower contact fixture being provided with apair of spaced side walls for receiving the laterally projecting part ofsaid lower contact fixture, and said walls being formed with inwardlyextending guide surfaces engaging the top of the ejector lever trunnionsto guide them backwardly and downwardly into backwardly and upwardlyopen bearing grooves carried by said walls, the pivotal movement of saidejector lever upon blowing the fuse moving the ejector trunnionsbackwardly and upwardly out of said grooves into an open space belowsaid guide means to release the trunnions by gravity from the lowercontact flxture.

2. In a fused drop-out cut-out, the combination of an insulating supportwith upper and lower spaced contact arms carried by said support. a fusetube unit comprising an insulating tube open at the bottom and closed atthe top, said tube having upper and lower contact fixtures andsupporting and enclosing a tensioned fuse engaging said xtures, bothsaid fixtures being provided with a pair of oppositely directed alignedtrunnions, and the upper contact arm being provided with open jaws forreceiving and supporting the upper trunnions for rotation, the lowercontact xture comprising a laterally projecting part extending towardthe lower contact arm and pivotally supporting an ejector lever, saidejector lever being attached at its end to the fuse and carrying thelower trunnions below the point of pivotal support of the ejector lever,spring means for urging said ejector lever about its pivot to tensionthe fuse and to move the ejector lever trunnions backwardly and upwardlyin an orbit, said lower contact fixture being provided with a pair ofspaced side walls for receiving the laterally pro- Jecting part of saidlower contact xture, and said walls being formed with inwardly extendingguide surfaces engaging the top of the ejector llever trunnions to guidethem backwardly and downwardly into backwardly and upwardly open bearinggrooves carried by said walls, the pivotal movement of said ejectorlever upon blowing the fuse moving the ejector trunnions backwardly andupwardly out of said grooves into an open space below said guide meansto release the trunnions by gravity fi'om the lower contact fixture, thesaid lower contact fixture being provided with second spring meansengageable by the ejector lever spring means, the said second springmeans serving after the ejector lever has moved to release its trunnionsto assist the force of gravity in expelling the lower contact xture fromthe lower contact arm.

3. In a fused drop-out cut-out, the combination of an insulating supportwith upper and spaced contact arms carried by said support. a lowerspaced Contact arms carried by Seid SUD- 'portafusetube nf unitcomprising an insulating tube open at the bottom and closed at theton.

said tube having upper and lower contact fixtures and supporting andenclosing a tensioned fuse eneasing said flxtureaboth lsaid xturesbeingprovided with a pair of oppositely directed aligned trunnions,andthe upper contact arm being provided with open jaws for receiving andsupportsaid lower contact iixture being provided with a pair of spacedsidewalls for receiving the laterally projecting part of said lowercontact xture, and said walls being formed with inwardly extending guidesurfaces engaging the top of the ejector lever trunnions to guide thembackwardly and downwardly into backwardly and upwardly open bearinggrooves carried by said walls, the pivotal movement of said ejectorlever upon blowing the fuse moving the ejector trunnions backwardly andupwardly out of said grooves into an open space below said guide meansto release the trunnions by gravity from the lower contact fixture, thesaid walls being joined by an upper wall forming a hood, and the saidhood engaging the top of said laterally projecting part of the lowercontact iixture to resist the jet action of the fuse tube unit uponblowing of a fuse.

4. In a fused drop-out cut-out, the combination of an insulating supportwith upper and lower spaced contact arms carried by said support, a fusetube unit comprising an insulating tube open at the bottom and closed atthe top. said tube having upper and lower contact fixtures andsupporting and enclosing a tensioned fuse engaging said fixtures, bothsaid fixtures being provided with a pair of oppositely directed alignedtrunnions. and the upper contact arm being provided with open jaws forreceiving and supporting the upper trunnions for rotation, the lowercontact xture comprising a laterally projecting part extending towardthe lower contact arm and pivotally supporting an ejector lever, saidejector lever being attached at its end to the fuse and carrying thelower trunnions below the-point of pivotal support of the ejector lever,

spring means for. urging said ejector lever aboutl its pivot to tensionthe iuse and to move the ejector lever trunnions backwardly and upwardlyin an orbit, said lower contact fixture being provided with a pair. ofspaced side walls for receiving the laterally projecting part oi' saidlower contact xture. and said walls being formed with inwardly extendingguide surfaces engaging the top of the ejector lever trunnions to guidethem backwardly and downwardly into backwardly and upwardly open bearinggrooves carried by said walls, the pivotal movement. oi' said ejectorlever upon blowing the fuse moving the ejector trunnions backwardly andupwardly out of said grooves into an open space below said,

guide means to release the trunnions by gravity from the lower contactiixture, the said walls being joined by an upper wall forming a hood,and the said hood engaging the top of said lateralLvprojecting part ofthe lower contact iixture to resist the jet action of the fuse tube unitupon mowing of a ruse, and said hood being;

downwardly curved at its forward end, tending to Vretain the lowercontact fixture until the jet action of the fuse tube unit ceases andthe cir- `cuit is broken, so that the lower contact fixture tion of aninsulating support with upper and lower spaced contact arms carried bysaid support, a fuse tube unit comprising an insulating, tube open atthe bottom and closed atthe top. said tube having upper and lowercontact iixtures and supporting and enclosing a tensioned fuse engagingsaid fixtures, both said fixtures being provided with a pair ofoppositely directed aligned trunnions, and the upper contact arm beingprovided with open jaws for receiving and supportting the uppertrunnions for rotation, the lower contact ilxture comprising a laterallyprojecting part extending toward the lower contact arm and pivotallysupporting an ejector lever, said ejector lever being attached at itsend to the fuse and carrying the lower trunnions below the point ofpivotal support of the ejector lever, spring means for urging saidejector lever about its pivot to tension the fuse and to move theejector lever trunnions backwardly and upwardly in an orbit,

said lower contact fixture being provided with a pair of spaced sidewalls for receiving the laterally projecting part of said lower contactxture, and said walls being formed with inwardly extending guidesurfaces engaging the top of the ejector lever trunnions to guide thembackwardly and downwardly into backwardly and upwardly open bearinggrooves carried by said walls, the pivotal movement of said ejectorlever upon blowing the fuse moving the ejector trunnions backwardly andupwardly out of said grooves into an open space below said guide meansto release the trunnions by gravity from the lower contact fixture, saidupper jaws comprising a pair of U- shaped wires, one on each side of thefuse tube unit, the U-shaped wires crossing each other behind the uppertrunnions, where they are formed with said jaws.

6. In a fused drop-out cut-out, the combination of an insulating supportwith upper and lower spaced contact arms carried by said support. a fusetube unit comprising an insulating tube open at the bottom and closed atthe top.

said tube having upper and lower contact fixtures and supporting andenclosing a tensioned fuse engaging said fixtures, both said fixturesbeing provided with a pair of oppositely directed aligned trunnions, andthe upper contact arm being provided with open jaws for receiving andsupporting the upper trunnions for rotation, the lower contact fixturecomprising a laterally projecting part extending toward the lowercontact arm and pivotally supporting an ejector lever, said ejectorlever being attached at its end to the fuse and carrying the lowertrunnions below the point of pivotal support of the ejector lever.spring means for urging said ejector lever about its pivot to tensionthe fuse and to' move the ejector lever trunnions backwardly andupwardly in an orbit, said lower contact fixture being provided with apair of spaced side walls for receiving the laterally projecting part ofsaid4 lower contact xture, and said walls being formed with inwardlyextending guide surfaces engaging the top of the ejector lever trunnionsto guide them backwardly and downwardly into backwardly and upwardlyopen bearing grooves carried by said walls, the pivotal movement of saidejector lever upon blowing the fuse moving the ejector trunnionsbackwardly and upwardly out of said grooves into an open space belowsaid guide means to release the trunnions by gravity from the lowercontact fixture, the said trunnions on the upper contact fixture beinglocated on that side of the tube unit which is away from the insulatingsupport, the jet action from the fuse tube tending to rotate the fusetube clockwise about the upper trunnions and tending to retain the lowercontact fixture in engagement with the lower` contact arm.

'7. In a fused drop-out cut-out, an upper contact structure comprisingan insulating support, metal band means extending about the insulatingsupport and having a pair of parallel flanges, a connector block locatedbetween said parallel flanges and having a pair of through boresregistering with bores in the flanges, said connector block having eachof its opposite faces formed with a forwardly open U-shaped groovefacing each flange, a pair of substantially U-shaped wire contactmembers, each contact member having curved portions clamped between saidflanges and spacer block, and said U-shaped wire contacts havingforwardly extending portions formed adjacent their ends with partiallycircular trunnion bearings.

8. In a fused drop-out cut-out, an upper contact structure comprising aninsulating support, metal band means extending about the insulatingsupport and having a pair of parallel flanges, a connector block locatedbetween said parallel flanges and having a pair of through boresregistering with bores in the flanges, said connector block having eachof its opposite faces formed with a forwardly open U-shaped groovefacing each flange, a pair of substantially U-shaped wire contactmembers, each contact member having curved portions clamped between saidflanges and spacer block, and said U-shaped wire contacts havingforwardly extending portions formed adjacent their ends with partiallycircular trunnion bearings, said contact wires crossing each otherupwardly and downwardly backward of said trunnion bearing portions.

9. In a fused drop-out cut-out, a lower contact structure comprising aninsulating support. a clamping band carried by said insulating support,a contact fixture secured to said clamping band by through bolts, saidcontact fixture having a downwardly extending rear wall, forwardlyextending parallel side walls, and a forwardly extending top wall, thesaid side walls being provided with inwardly facing recesses, eachrecess being open at the front edge of said side walls and extendingbackwardly toward the back wall and curving downwardly and forwardlyunder a rearwardly extending partition carried by each wall.

10. In a fused drop-out cut-out, a lower contact structure comprising aninsulating support,

. a clamping band carried by said insulating supvided with inwardlyfacing recesses, each recess being open at the front edge of said sidewalls and extending backwardly toward the back wall and curvingdownwardly and forwardly under a rearwardly extending partition carriedby each wall, the said through bolts carrying a fuse tube, and anejecting spring comprising a U-shaped spring member passing over onethrough bolt and under and about the other screw bolt.

11. In a fused drop-out cut-out, a lower contact structure comprising aninsulating support. a clamping band carried by said insulating support,a contact xture secured to said clamping band by through bolts, saidcontact fixture having a downwardly extending rear wall, forwardlyextending parallel side walls, and a forwardly extending top wall, thesaid side walls being provided with inwardly facing recesses, eachrecess being open at the front edge of said side walls and extendingbackwardly toward the back wall and curving downwardly and forwardlyunder a rearwardly extending partition carried by each wall, and a fusetube unit provided with a lower contact fixture having a rearwardlyextending part, said rearwardly extending part carrying a pair ofaligned oppositely directed trunnions receivable between said sidewalls, the said trunnions passing backwardly and about the end of saidpartition into a lower part of said recesses.

12. In a fused drop-outvcut-out, a lower contact structure comprising aninsulating support, a clamping band carried by said insulating support,a contact fixture secured to said clamping band by through bolts, saidcontact fixture having a downwardly extending rear wall, forwardlyextending parallel side walls, and a forwardly extending top wall, thesaid side walls being provided with inwardly facing recesses, eachrecess being open at the front edge of said side walls and extendingbackwardly toward the back wall and curving downwardly and forwardlyunder a rearwardly extending partition 'carried by each wall, and a fusetube unit provided with a lower contact fixture having a rearwardlyextending part, said rearwardly extending part carrying a pair ofaligned oppositely directed trunnions receivable between said sidewalls, the said trunnions passing backwardly and about the end of saidpartition into a lower part of said recesses, the said trunnions beingcarried by a pivoted ejector lever, spring pressed to move in such adirection as to withdraw the fuse and move the trunnions backwardly,upwardly, and forwardly out of said recesses.

DAVID C. HUBBARD. WILLIAM L. HOLLANDER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name V Date 1,958,496 Rah May 15,19342,212,633 Bodendieck Aug. 27, 1940 2,290,382 Ramsey July 21, 19422,446,676 Yonkersl Aug. 10, 1948

